Dental mandrel



Sept. 7,1926. 1,599,290

C. I. STOLOFF DENTAL MANDBEL Filed April 11, 1925 INVENIOR Charles I. sfoloff TORNEYS Patented 7 Sept. 7, .1926.

angent-m e CHARLES 1'. sucrose, or New YORK, N. Y.

DENTAL MANDREL.

Application filed April 11,1925; Serial to. 22,313.

dental mandrel of the type comprising a rotata-ble shaft having a work member such as a grinding or polishing implement detachably carried by one end of the shaft and designed and constructedto be receivable by the mouth of the patient, which work member -is detachably secured to the shaft by means of a securing device which is threadedlyreceivable' by the end of the shaft, and which is adjusted to hold the work member in secured relation onto and against'the end of the shaft. In practice, a single mandrel shaft is employed with any'of a variety of work members, and where the work member consists ofan abrasive orpolishing implement, the same may be in the form of a sand paper disk, .metal or carborundum disks, grinding stones, rubber caps and the like, these being interchangeably attachable f to the mandrel by the removal and adjust--- ment of the securing device in accordance with the character of the work to beperformed. e I

In mandrels of prior and known constructions, the work member is secured ,OIltO the mandrel shaft by the threaded adjustment of the securing device,the work member being held between the shaft end and the head.

of the securing device. In order to hold the work member in fixed relation on the shaft in these prior mandrel constructions, the threaded connection between the securing device and theshaft is made such-that the rotation of the work member will have a tendency to engage the head of the'securing device and move the latter into'tightened condition. HOW6V6l','lt has beenuniversally found in operation and use of these man-,

curing devices are not properly engaged by the rotatable work member, and that the work member is not held in fixed relation on the shaft, but rotates relatively thereto;

is rendered less efficient, the work member sometimes working'loose to anextent which prevents'its operation altogether, this neces 5 sitating removal of the mandrel from the drels that for one reason or 'another the se-' .mouth of the patient and {objectionable adjustment by the operating dentist. i U To overcome these objections and to improve upon the operation of these mandrels, it has been suggested to insert various elements between the head ofv the securing de vice and the work member, such as flat or 7 spring washersand the like, for the pur pose of assisting the automatic adjustment of the. securing device 1 during use of the mandrel. These flat or spring washers, however, have not materially improved the operation of the mandrel, and especially so after the work membershave been in service for a moderate period of. time. The spring washer inserted bet-ween the head of the secur ng device and the work member .has proved ineffective in use for a number of v reasons,'pri1ne among which are-that the engaging surface between the spring washer and the work member is small and hence in sufficient, and that such springwasher exerts an axialpush between thehead of the securing device and the work member which in large measure prevents by counteraction the axial adjustment-of the securing device. I have also found that another cause for the ineffective engagement between the parts to produce the desired.adjustmentis that the rotation of the work member is so rapid, as to be insufficient to overcome the inertia of s the securing device against tightening movement.

A prime desideratum of my present invention therefore comprehends the. provision of an improved mandrel construction in which the above-mentioned disadvantages inherent in prior structures are effectively overcome, and in which a-compensating means is pro-'* vided and arranged between the work member and the head of the securing device-designed and constructed to eliminate the dis,. advantages nherent in spring washer in-;

serts and to produce a mea'nswhich auto inatically effects the tlghtenlng of thesecuring device. andthus compensates for, all

looseness and consequent relative movement between the work member and the shaft in an effective and workable fashion To the accomplishment of the foregoing and such other objects as will hereinafter appear, my invention consists in the elements and their relation one-,to-the' other, as hereinafterparticularly described and; sought to be defined in the claims; reference being had to the accompanying drawings which show,

' ing my improvements applied thereto,

r of the Fig. 2 is a view'of the same showing the parts in detached relation, and

Fig. 3 is a view of a modification. Referring now more in detail to the drawings, the dental mandrel comprises a rotatable shaft 10 having an enlarged head 11 at one end thereof, the said shaft being provided at such end with an axially tapped.

bore 12 for receiving a correspondingly threaded portion 13 of a securing device generally designated as 14 and having a head 15, a work member 16 such as a grinding or polishing wheel or disk being removably attachable to the mandrel and secured between the enlarged head 11 of the shaft and the head 15 of the securing device 14.

With this construction of the mandrel, the work member 16, which may be a polishing, separating or grinding implement such as a sand paper disk, carborundum disk or grinding stone, etc., is removably attachable t0 the mandrel shaft and is secured in fiXed posi tion on the shaft by means of the adjustment securing device 14. As has been explained, the work' member 16 works itself loose in'p'ractice, with a consequent annoyance both to patient and dentist due to the improper functioning thereof; and to overcome the above-mentloned ob ections and disadvantages inherent in known mandrel constructions, my present invention com-- prises the introduction of means between the outer face 16 of the work member and the contiguous 'end of the head 15 of the securing device which functions to automatically tighten the securlngdevice onto the mandrel shaft'lO and thus automatically adjust and compensate for any tendency towards relative movement between the work member 16'and the mandrel shaft 10.

In the preferred construction of the invention as shown in Figs. 1 and 2 of the drawings, the means for effecting the auto inatic tightening of the securing device comprises an element 17 arranged to engage the outer face 16 of the work member and located between the same and the head 15 of the securing device and a resilient member 18 connecting the said element 17 and the head 15 of the securing device, the connec tion being such as to permit yieldable relative rotation betweenthe element 15 and the said head of the securing device.

More specifically in the preferred embodiment the engaging element 17 is flat or diskshaped so as to provide for maximum frictional surface contact between the same and the out r face 16 of the work member, and the resilient member '18 preferably com prises a helical spring" having one end 18 fixedly connected to thefiat-shaped washer element 17 and having the other end 18 fixedly attached to the securing device head 15. I have found, however, that the attach ment of only one end of the spring is sufti- 18 may be appropriately concealed and' housed by the head, as clearly shown in Fig. 1 of the drawings.

By the provision of this d'scribed construction, I have found that the outer face 16 of the work member 16 always engages the contiguousface of the washer element 17, the same being urged axially into engagement with the work member by the helical spring 18, and that the frictional engagement is more thanample to act upon the head 15 of the securing device through the intermediationof the spring 18 to cause the said securing device to adjust itself into tightened condition. The spring 18 preferably is con'iparatively light, so that it will have no tendency by its axial action to oppose the rotation of the securing device into tightened position, the spring 18 functioning more in the nature of a connecting means between the washer 17 and the head of the securing device which permits that partial and yieldable relative rotation between the washer 17 and the head of the effect the automatic take-up: of the adjusting screw with certainty. 7,

Referring now to Fig. 3 of the drawings, 1 show a modification of the invention in which the mandrel comprises a shaft 10 having the enlarged head 11 and axial bore receiving a securing device lt having a construction similar to that heretofore described, and including a threaded shank 13 and a hollow or cup-shaped head 15, a work member 'such as a sand paper disk 16 being receivable between the parts of the mandrel. In this form of my invention, however, I eliminate the washer 17 and employ the helical spring 18 which is attached tothe head 15 as the means for producing thedesired results, the said helical spring being flattened at its bottom so as to engage the 'outer face of the work member 16, the said flattened bottom being the equivalent of the ings, but I have foundthat the frictional engagement combined with the torsional action of the spring on the head of the securing device is sufficient to produce that rotative movement of the securing device desired for automatically tightening the ceivable by said here and a head portion sociated with the work member to secure the same on the shaft and against'the said end thereof, and means for holding the work nember in secured relation on the shaft and for automatically tightening the securing device and thus compensating for looseness and consequent relative movement between the work member and the shaft, said means com-- prising an element engaging the outer face of the work member and a-rrangedvbetween the sameand the head of the securing device and a resilient member having tor sional and aaial resilient componentsconnecting the said element: and the said head,

the connection being such as to permit yield-= able relative rotation between the said element and the said head of the securing device. r

2. A mandrel comprising a rotatable shaft having an axially tapped bore at one end thereof, a work member detacliahly carried by the shaft at said end, a securing device having a shank portion threadedly receivable by said bore and ahead portion associated with the work member to secure the same on the shaft and against the said end thereof, and means for holding the work member in secured relation on the shaft and for automatically tightening the securing device and thus compensating for looseness and consequent relative movement between the work member and the shaft, said means comprising a flat-shaped element engaging the outer face of the work member and "arranged between the same and the head of the securing device and a. resilient member fixedlyconnected at opposite ends to the said element and the said head, the connection being such as to permit partial and yieldable relative rotation between the said element and the said head of the securii'ig device. I

3. A mandrel comprising a rotatable shaft having an axially tapped 1 bore at one end thereof, a work member detachably carried by the shaftat said end, a securing device member detachably car having a shank portion threadedly receivable by said bore and a head portion asso.

ciated with'the work member to secure the same on the shaft and against the said endthereof, and means for holding the work member in secured relation on the shaft and for automatically tightening the securing device and thus compensating for looseness and consequent relative-mov i the work member and the shart, said means comprising an element engaging-"the outer face of the work member and arranged between the same and the head of the securing device and a helical spring connecting the said element and the said'head.

nent between I 4. A mandrel comprising a rotatable shaft having an axially tapped here at oneend thereof, a work member detachably carried by the shaft at said end, a securing device having a shank portion threadedlyreceivable by said bore and a cup-shaped head portion associated with the work member to securing dc *ice and thus compensating for secure the same on the shaft and against the looseness and consequent relative movement between the work member and the shaft,

said means comprising an element engagii'wg the outer face of the work member and arranged between the same and the headof the securing device. and a helical spring connecting" the said element and the said cupshaped head and arranged to 'be concealed within and housed by the said head. 7

i 5. A mandrel comprising a rotatable shaft having an axially tapped bore at one end thereof, a work member detachably carried bythe shaft at said end, a securing device having a-shank nortion threadedly receiv' able'by said bore and a cup-shaped head portion associated with thework member to secure the same on the shaft and'against the said end thereof, and means for holding the work member in secured relation on the shaft and for automatically tightening the securing crevice and thus compensating for looseiiess and consequent relative movement between the work member and the shaft, said means comprising a fiat washer element engaging the outer face of the work member and arranged between the same and the head of the securing device and a helical spring fixedly connected at opposite ends to the said element and the said cup-shaped head and arranged to be concealed within and housed by the said head, the connection being suchoas to permit partial and yieldable relative rotation between the said element and the head of the securing device. Signed at New York city, in the county of New-York and Stateof New Yorkthis 10th day of April v CHARLES I. STOLOFF. 

